function getXMLHttpRequest(){
	if(window.ActiveXObject){
		try{
			return new ActiveXObject("Msxml2.XMLHTTP");
		}catch(e){
			try{
				return new ActiveXObject("Microsoft.XMLHTTP");
			}catch(e1){return null;}
		}
	}else if(window.XMLHttpRequest){return new XMLHttpRequest();}else{
		return null;
	}
	
}
var httpRequest=null;
function sendRequest(url,params,callback,method){
	httpRequest=getXMLHttpRequest();
	var httpMethod=method?method:'GET';
	if(httpMethod!='GET'&&httpMethod!='POST'){
		httpMethod='GET';
	}
	var httpParams=(params==null||params=="")?null:params;
	var httpUrl=url;
	if(httpMethod=='GET'&&httpParams!=null){
		httpUrl=httpUrl+"?"+httpParams;
	}
	
	httpRequest.open(httpMethod,httpUrl,true);
	httpRequest.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
	httpRequest.onreadystatechange =callback;
	httpRequest.send(httpMethod=='POST'?httpParams:null);
}